Press clutch



Feb. 28', 1939. J, D LE FRANK 2,148,481

PRESS CLUTCH Filed June 6, 1954 2 Sheets-Sheet 1 fig j fr if ATTORNEY;

Feb. 28, 1939. J, D. LE FRANK PRESS CLUTCH Filed June 6, 1934 2 Sheets-Sheet 2 ATTORNEM Patented Feb. 28, 1939 UNITED STATES PRESS CLUTCH John Daniel Le Frank, Maplewood, N. J., assignor to American Can Company, New York, N. Y., a corporation of New Jersey Application June a, 1934, Serial No. 129,323 '11 Claims. (01. 192-56) The present invention relates to a clutch mechanism for presses and the like and has more particular reference to the holding of the connecting clutch parts with different yieldingpresi sures, the starting of the press operation with the relatively great inertia of the press load which must be overcome requiring a greater pressure than is required after the press parts are moving, the automatic selection of the proper yielding pressures which is provided for in the invention producing a sensitive self adjusting slip connection which is compatible with'the clutch force required.

An object of the present invention is the provision of a clutch mechanism which includes a slip connection between the driving and the driven parts which is maintained by yielding forces, one set of forces applying when the operating parts of the press are first moved and :0 another set holding the clutch connection after the press is operating.

Another object of the'invention is the pro- .vision of clutching instrumentalities for a press clutch which are in part actuated by a starting :5 holding force automatically held dormant but maintained in an operable position as long as the press is not under operation, this force becoming active during starting of the press and being automatically nullified and inoperative :0 after the press parts have been brought under operating movement.

A further object of the invention is the provision of a latch device in a press clutch of the character described which is cooperatively assom ciated with a relatively strong yielding pressure force forholding the clutch parts in clutching position to permit starting of the press with its attendant load and to overcome the inertia of the load, this latch being automatically thrown n out of cooperative position to nullify the stronger yielding force after the press has been started.

Yet another object of the invention is the pro-.

vision of a slip clutch mechanism in which driving and driven members are yieldingly held conla nected for operation of the press, the holding of this connection being just sufflcient to permit operation of the press after the parts have begun their movement and thus providing a sensitive slip clutch to permit disconnection'of the driving 9 and driven members upon the establishment of abnormal conditions, together with other holding yielding devices which are brought into play only when the press is first started and the inertia of its stationary load first overcome.

A further object of the invention is the provision of yielding holding devices of a slip clutch of the character described wherein a greater yielding holding force is effective only when a latch device is in a certain position, this latch device being thrown out by centrifugal force as 5 soon as the operating parts of the clutch begin their movement so that the greater holding force associated with the latch is nullified and the holding devices are then yieldingly held under a lesser holding force.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses. a preferred embodiment thereof.

Referring to the drawings:

Figures 1 and 2 are longitudinal sectional views partly in elevation of associated clutch parts embodying the present invention, Fig. 1 showing the clutch connected for driving and Fig. 2 showing the clutch thrown out of driving connection;

Fig. 3 is a transverse sectional view partly broken away taken substantially along the line H in Fig. 1;

Figs. 4 and 5 are transverse sectional details of a part of the clutch mechanism being taken substantially along the lines 4-4 and 5-5 in Fig. 1 and showing different positions of the parts;

Fig. 6 is a similar transverse sectional view taken substantially along the line 66 in Fig. 2; and

Fig. 7 isa perspective view of a part of the driven shaft of a press or other apparatus and showing its connection with a clutch locking key.

A preferred embodiment of the present invention as illustrated in the drawings comprises a driven shaft ll v (Figs. 1 and 2) which may be iournaled in a hearing If. This shaft may constitute the principal driven shaft of a press or other suitable apparatus and is used in this description to indicate any working parts of such an apparatus whlchare set in motion through the intermediary of the clutch.

Shaft II is reduced at its end in an extension l3 which carries a sleeve hub ll of a disc IS, the hub being secured to the end of the shaft extension by a pin l6 so that disc and shaft move together. The hub i4 extends beyond the end of the shaft. The disc I5 constitutes the driven part of the clutch mechanism.

A clutch body fl is loosely mounted on the reduced end It of the shaft Ilanr'. one face is countersunk at 22 to accommodate the disc II. n;

Body 2| is connected with a sprocket 23 by a pin 24 the sprocket being also mounted on the end of the shaft. The clutch body and sprocket constitute driving parts of the clutch mechanism and driving power may be applied to the sprocket in any suitable manner.

It should be understood that in starting the press or other apparatus, the driving member oi the clutch is first rotated by power applied 'to its sprocket 23 and through the clutch mechanism this rotation is imparted to the shaft II and other parts of the press associated therewith. Furthermore, such rotation of the sprocket is usually continued for one complete turn which constitutes one operating cycle.

A washer 25 is preferably mounted on the shaft section I3 to serve as a thrust bearing for the sprocket 23, this washer being located adiacent the bearing |2 of theshaft The hub of the driven disc I5 carries a ring 26 which is secured tothe face of the clutch body 2| by pins 21. One face of this ring is adjacent to the disc I5 and holds the latter within its seat 22, the ring with its clutch body being free to move relative to the disc except for connecting clutch instrumentalities which will now be described.

The ring 26 (Figs. 1 and 3) is cut through in spaced horizontally disposed openings 28 in which clutch pins 29 are located. There are three openings and three clutch pins illustrated in' the drawings but the exact number is immaterial.

Each clutch pin 29 is formed with a conical inner face 3| which is adapted to seat within a conical countersink 32 formed in the adjacent face of the disc I5 when the clutch is in its clutched or connected position.

The clutch pins are held under yielding pressures being backed up by a sliding disc 35 having a hub 36 which is loosely mounted on the hub l4 of the disc IS. A collar band 31 is mounted on the outside of the hub 36 and supports encircling coils of a spring 38 one end of which engages the outer face of the disc 35.

The opposite end of spring 38 is held against a pair of ring segments '38 (Figs. 1 and 4) which are also mounted on the end of the hub I4 of the disc l5. The ring segments are counterbored at 4| and segmental keys 42 are interposed between the ring segments and the hub l4 and are held in a groove 43 cut in the hub. These keys provide stops for the ring segments 39, this construction holding the spring 38 under a predetermined compression so that it exerts a given pressure against the outer ends of the clutch pins normally holding the latter in their seats 32 in the disc II. A collar housing 45 is also carried on the end of the disc hub l4. This collar is secured to the ring segments 39 by bolts 46 (Figs. 4 and 5) and is prevented from turning on the disc hub M by a key 41.

Spring 38 is the light pressure spring which is used to hold the clutch pins in clutched position while the press is rotating. By maintaining this spring relatively light in its action the clutch is made sufliciently sensitive to throw out when abnormal conditions place an undue strain upon the rotating driven shaft II. It is sufficient, however, in its holding action to maintain the clutched position of the clutch pins during the normal operation of the press shaft H.

An abnormal condition set up while the press .is operating throws an excessive strain upon the shaft and this, if the strain is sufficient, holds the disc l5 against rotation. Thereupon the driving members including the clutch ring 26 move relative to the disc l5 and the inclined ends 3| of the clutch pins 28 ride out of their seats 32 as the spring 38 yields and the disc 35 moves back into the unclutched position of Fig. 2. The relatively heavy driven mechanism of the press thereupon ceases operation, augmented by theabnormal load or strain imposed upon the shaft II to bring about the described disengagement of the clutch, and the tension of the light pressure spring 38 is insufficient to thereafter force the tapered clutch pins 29 into successive registering countersinks 32 in the driven disk I5 with sufllcient pres sure to again reestablish the driving engagement. Therefore the said pins merely ride in and out of the countersunk bores 32 until the abnormal strain or load has been relieved or corrected.

The operation of the clutch just considered relates to the slipping action incident to the press parts in motion. Consideration will now be given to that other stronger or greater resisting clutch holding feature which has only been suggested heretofore and which relates to the starting of the driving and driven members from a dead stop.

A sleeve 5| (Figs. 1, 2 and 4) is inserted in the outer end of the disc hub 14 and projects beyond the end of the hub being also located on the inside of the collar 45 and partially encloses the heavy spring unit now being considered. This unit comprises a pin 52 which is formed with a head 53 the head being adjacent the outer wall of the collar 45. The opposite end of the pin 52 protrudes into the open end of a bore 55 which is formed in the end of the reduced section 3 of the shaft Pin 52 is slotted at 56 and an elongated key 51 (see also Fig. 7) is confined within the slot.

The key 51 extends out from both sides of the pin being loosely confined within a slot 58 cut in the end of the shaft section l3. The key 51 passes through aligned slots 6| cut in the hub H of the disc l5. The ends of the key 51 beyond the disc hub l4 extend into aligned slots 62 cut in the hub 36 of the sliding disc 35. The key is held against longitudinal movement and within the various slots by the collar band 31.

A heavy spring 85 is mounted on the pin 52 and is confined between the head 53 of the pin and a washer 66 mounted on the pin and engaging one side of thekey 51. This spring is fully located insideof the sleeve 5| and the disc hub l4 and is passive or ineffective as long as the key 51 is held in the pin end of the pin slot 56, i. e., to the right of the slot as in bothFigs. l and 2. As long as the spring 38 is sufllcient in strength to hold the clutch pins in their clutched position (Fig. 1) the spring 65 is passive, this being the setting of the parts just prior to starting the machine.

Provision is made'for inserting a latch element between the end wall of the collar 45 and the head 53 of the pin 52. The collar 45 is cut away from one side to form a space 68 adjacent its outer wall (see Figs. 5 and 6). A latch 1| is pivotally mounted on a pin 12 which is carried in the collar 45 and this pin extends across the cut out space.

Latch 1| is formed with an inner arm 13 and an outer arm 14 the former being located in the space 68. When the press comes to a stop after each operation the collar 45 is brought into the position illustrated in Figs. 1 and 5' with the.

space- 68 on top. The outer arm 14 of the latch unde the action of gravity thereupon brings its inner arm 13 into vertical position where it e gages a stop pin inserted through the end wall of the collar 45 and projecting into the space 68.- In this position the end of the arm II is adjacent the head 53 of the pin 52 and these parts remain so until the press begins movement.

In beginning the operation of the press .or other mechanism by rotating the sprocket 23 the overcoming ofthe inertia of its load, which must be picked up through the clutch, tends to cause the clutch pins 29 to ride out of their seats, the spring 88 being too weak to prevent this. The disc 35 does start moving (toward the left Fig. 1) sumciently to shift the heavy spring unit by movement of the key 51. The head 530! the pin 52 immediately comes into engagement with the arm 13 of the latch II and the spring 65 thereupon is placed into an eifective condition.

Any further movement of the sliding disc 35 must now overcome the resistance of the heavy spring. This resistance is predetermined so that it is just suflicient to prevent the disc 35 from moving far enough to disengage the clutch pins 29 if there is a normal starting load on the press shaft ll. With a normal load, accordingly, the pins are held in clutched position until the driven shaft II and parts connected therewith are picked up and'rotated in unison with the drive sprocket 23.

As soon as these parts begin rotating the inertia of the load is relieved and thereafter the spring 38 is suflicient to hold the clutchin clutched position and the heavy spring unit is shifted back in the position of Fig. 1 and the head 53 of the pin 52 moves away from the arm 13 of the latch H.

The centrifugal forces which by this time have been set up by the rotating shaft and connected parts apply directly to the latch arm I4 and cause a pivoting of the latch 'i l into the position shown in Fig. 6 where the arm 13 engages against a stop pin 16 which like the pin 15 is similarly carried in the collar 45. In this latter position the arm 13 is clear of the head 53 of the pin 52 and throughout the remaining portion of the cycle of operation, or as long as there is rotative movement of the press shaft, the spring 38 is effective in holding the parts in clutched position.

In the event that there is an abnormal starting load or an excess blocking of the shaft I l as the driving power is applied to the sprocket 23, the rotating ring 26 sweeps the clutch pins 29 out of their seats within the disc l5 as the heavy spring 65 yields. This prevents damage to the machine in starting. v

It will thus'be observed that during the starting of the press the heavy spring unit is effective so that as long as there is the normal load of the apparatus to be picked up with the starting of the driving member parts the driving and driven members will be maintained in clutched position. In the event, however, that an abhor-- 'mal condition obtains at such a time the heavy spring unit yields sufficiently to prevent damage to the machine.

As soon as the apparatus begins its movement the heavy sp g unit is thrown out of action and its eifect is completely nullified and thereupon the lighter spring unit of the clutch retains the-driving and driven members in clutched relation as long as normal operating conditions obtain. In the event of an abnormal condition the light spring unit is sufiiciently sensitive to prevent any, damage to the apparatus and at such time the connecting parts will become unclutched.

It is thought that the invention andmany oi its attendant. advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope oi the invention or sacrificing all of its material advantages, the form hereinbefore described ,being merely a preferred embodiment thereof.

I claim:

1. In a clutch mechanism for a press, the combination of a driving member, a driven member, clutch instrumentaiities for connecting the driving and the driven'members, a plurality of yielding means for exerting difierent pressures on said instrumentalities in accordance with the load on said driven member to hold the said driving and driven members connected, and

.means movable in a plane transverse to the axis of said members for nullifying the greater of said holding means after the pressis operating.

2. In a clutch mechanism for a press, the combination of a driving member, a driven member, clutch instrumentalities for connecting the driving and the driven members, a pair of yielding means for exerting different pressures on said instrumentalities in accordance with the load on said driven member to hold the said driving and driven members connected, means for utilizing both pressures in starting operation 01' the press from a dead stop, and means movable centrifugally in a plane transverse to the longitudinal axis of said members for nullifying the greater of said holding means after the press is operating. r

. 3. In a clutch mechanism for a press, the combination of a driving member, a driven member, clutch instrumentalities for connecting the driving and the driven members, yielding means for holding said instrumentalities in connected position with a predetermined pressure during operation of the press, and a second yielding means controlled by said first mentioned means when the driving member first begins its movement for holding said instrumentalities in connecting position with a greater pressure to overcome the startinginertia of-the load on the press, said second yielding means being bodily movable relative to one of said members and said first mentioned yielding means to release the holding pressure of said second yielding means after the starting inertia of the press load has been overcome.

combination or a driving member, a driven member. clutch instrumentalities for connecting the drivingand the driven members yielding means for holding said instrumentalities in connected position with a predetermined pressure during operation of the press, and asecond yielding means set into eifective action by the yielding of said first mentioned yielding means when the driving member begins its movement and for holding said instrumentalities in connecting position with a pressure in excess of the pressure of said first mentioned yielding means to overcome the starting inertia of the load on the press, said second yielding means being bodily movable relative to one of said members and said first mentioned yielding means to release the holding pressure of said second yielding means after the starting inertia of the press load has been overcome.

4. In a clutch mechanism for a press, the l with said second yielding means when the press.

is started from a stop position to prevent sliding of said heavy spring unit and through its spring to prevent sliding of said sliding disc in order to overcome the starting inertia of the load on the press.

6. In a clutch mechanism for a press, the combination of a driving member, a driven member, clutch instrumentalities for connecting said driving and driven members, and a plurality of spring members for exerting different pressures on said instrumentalities in accordance with the load on said driven member to hold the said driving and driven members connected, one of said spring members being axially slidable relative to said driven member after exerting its respective pressure.

'1. In-a clutch mechanism for a press, the combination of a driving member, a driven member, clutching instrumentalities for connecting the said driving and driven members, and a plurality of spring members for exerting pressure on said.

instrumentalities to hold them in connecting position, said holding pressure being controlled in part by a said spring member which is bodily and axially movable relative to said driven member after exerting its respective pressure to start operation of the press.

8. In a clutch mechanism for a press, the com" bination oi a driving member, a driven member,

clutching instrumentalities for connecting the said driving and driven members, a plurality of spring elements for exerting pressure on said instrumentalities to hold them in connecting position, said holding pressure being greater at the starting of operation of the press, and means engaged by' only one of said spring elements and slidably operative relative to said members each time the press is stopped to condition the said greater holding pressure foreifective use when required for starting.

9. In a clutch mechanism, the combination of a driving member, a driven member, clutch instrumentalities for connecting said driving and driven members, a pair 01 independent concentrically disposed spring members for exerting light and heavy pressures on said instrumentalities, and means slidable axially relative to said members and engaging one only of said yielding means for selectively utilizing said pressures,

whereby the said light pressure is eflective on said instrumentalities after the starting load has been picked up under said heavy pressure.

10. In a clutch mechanism, the combination of a driving member, a driven member, clutch instrumentalities for connecting the driving and driven members for a combined rotative movement, said instrumentalities including a sliding clutch pin carried by one 01 said members and engageable with the other, yielding means for holding said clutch pin -in clutched position, and a latch device pivotally mounted for movement in a plane parallel to the plane defined by the rotative movement of said members for preventing yielding action of said yielding means in starting rotary movement of the clutch from a dead stop, said latch device being automatically movable by centrifugal action after normal rotary speed has been obtained to nullify its preventing action on said yielding means.

11; In a clutch'mechanism for a press, the

combination of a driving member, a driven memfrom a dead stop, said latch member being automatically movable by centrifugal action in a plane transverse to the longitudinal axis of said members after the press is operating to permit yielding action by said yielding means.

' JOHN DANIEL LE FRANK. 

